Since the first discovery of cancer stem cell (CSC) of acute myeloid leukemia (AML) in 1994, the identifications of CSCs were further demonstrated in breast cancer, brain cancer, liver cancer, colon cancer, lung cancer and pancreatic cancer. Besides the self-renewal activity of normal stem cell, CSCs are resistant to chemotherapy, radiotherapy, hypoxia, and immune-surveillance. In addition, CSCs are thought to be the major reason of cancer relapse.
There remains a need for an agent which specifically targets to cancer stem cells, for therapeutic, imaging and other purposes.